Core drill construction



Patented Aug. 10, 1937 UNlTE STATES 2,08QASZ PATENT ()FHCE CORE DRILL CONSTRUCTION Application January 14, 1936, Serial No. 59,076

5 Claims.

The invention relates to well drilling tools and relates more particularly to a core drill construction. A general object of this invention is to provide a core drill embodying an improved, de-

5 pendable and simple valve means for the inner barrel of the drill.

Another object of this invention is to provide a core drill assembly in which the valve is eiTectively secured to the upper end of the inner barrel with- 10 out cutting threads on the inner barrel whereby the inner barrel may have a thin wall to be light in weight. In core drills having inner barrels and especially in core drills haw'ng rotatably supported inner barrels it is very desirable to make 15 the inner barrels as light in weight as possible. It has been the usual practice to thread the valve to the upper'end of the inner barrel of a core drill, which has made it necessary to form the inner barrel with a relatively thick wall to carry the threads. In accordance with the present inven- 'tion the valve is 'dependably secured to the inner barrel without employing threads so that the inner barrel may be very light in weight.

Another object of this invention is to provide a 25 core drill construction in which the valve may be easily and quickly applied to and removed from the inner barrel when the inner barrel is removed from the outer barrel and in which the valve cannot become displaced when the tool is assembled 30 for operation.

A further object of this invention is to provide a core drill construction of the character mentioned that is simple and very inexpensive.

The various objects and features of our inven- 35 tion will be fully understood from the following detailed description 'of a typical preferred form and application "of the invention, throughout which description reference is made to the accompanying drawing, in which:

40 Fig. 1 is a side elevation of a core drill embodying the present invention with a portion of the outer barrel broken away to show the valve and the upper part of the inner barrel in side elevation. Fig. 2 is an enlarged vertical detailed 45 sectional View of the valve being a View taken as indicated by line 22 on Fig. 3 and Fig. 3 is a horizontal detailed sectional view taken as indicated by line 3--3 on Fig. 2.

The core drill in which the present invention 50 is embodied includes, generally, an outer barrel l0 carrying a suitable core cutting head or bit I I, an inner barrel I2 within the outer barrel It for receiving the core, a valve I3 for the upper end of the inner barrel l2 and means M for removably securing the valve 13 to the inner barrel I2.

The outer barrel I0 is an elongate tubular structure adapted to be connected with the lower end of a string of drill pipe. A suitable sub l5 may be provided on the upper end of the outer barrel it to facilitate its connection with the drilling string. 5 The particular sub i5 illustrated has a tapered screw threaded pin It for cooperating with a socket in the lower end of the drilling string. The head or bit H is shown secured to the lower end of the outer barrel in by a connecting memher or sub [7. The bit H has cutting means for making an annular cut in the earth formation to leave a core for reception in the inner barrel 12.

In accordance with the broader aspects of the invention, the outer-barrel It may be provided with any suitable form of cutting head or bit. The particular bit II shown in the drawing has circumferentially spaced blades 18 for making an annular cut in the formation. Ports l9 are provided in the bit l I at points between the blades I8 20 for discharging the circulation fluid.

The inner barrel i2 is an elongate tubular assembly or structure arranged longitudinally in the outer barrel ill to receive the core. The inner barrel l2 may be supported at its lower end in the bit H or the sub ll. The present invention is not concerned with the details of the means for supporting the inner barrel l2 and details of the mounting means for the inner barrel have been omitted from the present disclosure. The inner barrel l2 may have comparatively thin walls to be light in weight and to receive a larger core.

In the particular construction shown in the drawing, a tubular extension 20, having a relatively heavy wall, is welded to the upper end of the inner barrel l2. It is to be understood that this extension 20 is not essential. The inner barrel I2 is spaced from the interior of the outer barrel ID to leave an annular passage 2| for conducting the circulation fluid downwardly to the discharge ports I 9.

The valve I3 is provided on the upper end of the inner barrel I2 to prevent the downwardly flowing circulation fluid from entering the upper end of the inner barrel and is operable to permit the discharge of fluid from the inner barrel [2 as it is displaced by the entering core. Divisional application Serial No. 88,991 specifically describes and claims a valve similar to. the valve IS. The valve 13 includes a body 22 whose lower portion is entered in the longitudinal opening 23 of the inner barrel l2 and whose upper portion projects beyond the upper end of the inner barrel. An annular downwardly facing shoulder 24 is provided on the valve body 22 to seat downwardly against the upper end of the inner barrel or, as shown in the drawing, to seat downwardly against the upper end of the inner barrel extension 20. A central socket or opening 25 extends upwardly in the valve body 22 from its lower end and communicates with the opening 23 of the inner barrel. The upper portion of the valve body 22 which extends upwardly from the inner barrel or the inner barrel extension 20 is shaped to divert the downwardly flowing circulation'fluid. In the preferred construction, this projecting cage portion of the valve body 22 is hemispherical as illustrated. The projecting upper portion of the valve body 22 is chambered having a valve chamber 25. Circumferentially spaced lateral ports 21 extend outwardly from the chamber 25 and may have comparatively large mouths at the exterior of the body for communicating with the fluid space in the outer barrel ill.

The valve body 22 has a central opening 23 of reduced diameter connecting the opening 25 with the chamber 25. A hardened replaceable valve seat 35 is provided in the opening 28. It is preferred to thread the seat 30 in the opening 28 and the invention provides a simple effective means for positively locking the valve seat 30 against unthreading. Notches 3| are provided in the lower end of the valve seat 35 and following the proper threading of the seat in the opening 28, a bar 32 is inserted in the notches 3i and is then welded to the body 22. The bar 32, cooperating with the notches 3| and welded to the valve body as at 33, dependably prevents unthreading and displacement of the valve seat 35. The bar 32 in addition to locking the seat 30 in place, forms a strainer for preventing large objects from passing upwardly through the seat 30. The valve E3 includes a valve proper or ball 34 arranged in the chamber 26 to cooperate with the upper end of the seat 30. When the ball 34 seats downwardly against the seat 35 it effectively prevents the entrance of the circulation fluid to the upper end of the inner barrel l2.

The means M for removably securing the valve [3 to the inner barrel i2 is an important feature of the invention. The means l4 includes one or more latches 35 on the valve body 22 for cooperating with the inner barrel I2. In the particular form of the invention illustrated, there are four latches 35 equally spaced about the valve body 22. The upper ends of the latches 35 are pivotally connected with the valve body 22 above the upper end of the inner barrel l2 or the inner barrel extension 20. Webs 36 occur on the valve body 22 between the mouths of the ports 21 and recesses 37 are provided in the outer sides of the webs 36. The upper portions of the latches 35 project into the recesses 3'! and pivot pins 38 are carried in openings in the webs 35 and extend through openings in the latches 35 to pivotally connect the latches with the valve body 22. The latches 35 are comparatively long and are adapted to extend longitudinally or downwardly at the exterior of the inner barrel or the inner barrel extension 20. Inwardly projecting lugs 39 are provided on the lower ends of the latches 35. The lugs 39 are preferably round or substantially cylindrical to extend through lateral openings 40 in the wall of the inner barrel l2 or the inner barrel extension 25. Circumferentially spaced openings or sockets i! are provided in the exterior of the valve body 22 to communicate with the openings 40. The lugs 33 of the latches 35 are adapted to extend through the openings 49 and project into the sockets M. The latch lugs 39 and the openings 40 and the sockets M receiving the latch lugs may be comparatively large in diameter as illustrated in Fig. 2 of the drawing. The cooperation of the latch lugs 39 with the openings 4!] and the sockets 4i dependably locks the Valve body 22 against displacement from the inner barrel l2.

The latches 35 just described are proportioned so that their outer sides have slight clearance in the outer barrel Hi. This relationship between the latches 35 and the outer barrel l positively prevents the release or outward pivoting of the latches 35 when the inner barrel !2 with its valve l 3 is assembled or positioned within the outer barrel. The latches 35 also act as bumpers or centralizing ribs for maintaining the upper portion of the inner barrel centralized in the outer barrel ii). In assembling the valve l3 on the inner barrel l2, the valve body 22 may be arranged on the upper end of the inner barrel or the inner barrel extension 23 to have its shoulder 22 properly cooperate therewith. Following the seating of the valve body 22, it may be turned to bring the sockets M in proper alignment or register with the openings 40. The latches 35 may then be swung or pivoted to enter the lugs 39 in the openings 30 and the sockets 41'. The inner barrel l2 may then be assembled in the outer barrel In.

In the operation of the core drill, the outer barrel ii! is connected with the lower endrof the drilling string and the string is rotated and fed downwardly in the well to cause the bit H to cut into the earth formation. The circulation fluid is pumped downwardly through the drilling string to flow downwardly through the passage 2i and discharge from the ports IS. The valve or ball 34 cooperating with the seat 33 efiectively prevents this downwardly flowing fluid from entering the upper end of the inner barrel. As the core formed by the bit ll enters the inner barrel l2, fluid may be displaced from the inner barrel causing the ball 34 to rise from its seat 30.

The latches 35 dependably and securely attach the valve body 22 to the inner barrel l2. The

lugs 39 of the latches 35 fitting in the openings 45 and the sockets 4| positively prevent longitudinal movement and displacement of the valve body 22. It will be understood that the cooperation of the lugs 39 with the openings 40 and the sockets 4! may relieve the pivot pins 38 of all stresses. The latches 35 fitting the outer barrel Ill with only slight clearance cannot pivot outwardly sufficiently to allow their lugs 39 to move from the sockets 4|. Accordingly, as long as the inner barrel I 2 remains in the outer barrel I 0 its valve l3 cannot become displaced. Following the removal of the inner barrel l2 from the outer barrel H! at the termination of the drilling operations, the valve l3 may be easily removed from the inner barrel I2 by pivoting the latches 35 upwardly. The valve l3 with its latches 35 is a simple inexpensive structure. The openings 40 and the sockets A! for receiving the latch lugs 39 may be simple bores.

Having described only a typical form and application of our invention, we do not wish to be limited or restricted to the specific form and application herein set forth, but wish to reserve to ourselves any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described our invention, we claim:

1. In a core drill, a barrel having an opening in its wall, a valve removably arranged in the barrel and exposed at its upper end, there being a lateral opening in the valve, a latch pivoted on the exposed end of the valve, and a part on the latch cooperating with said openings to secure the valve to the barrel.

2. In a core drill, an outer barrel, an inner barrel arranged in the outer barrel and having an opening in its wall, a body in the upper portion of the inner barrel having an opening regist ring with the first named opening, and a pivoted latch cooperating with the openings to attach the body to the inner barrel and proportioned to be retained in the openings by the outer barrel.

3. In a core drill, an outer barrel, an inner barrel arranged in the outer barrel and having an opem'ng in the wall, a body in the upper portion of the inner barrel having an opening registering with the first named opening, and a latch pivoted on the body and retained in cooperation with the openings by the outer barrel.

4. In a core drill, an outer barrel, an inner barrel arranged in the outer barrel and having an opening in its Wall, a valve for the inner barrel comprising a body in the upper portion of the inner barrel having an opening registering with the first mentioned opening, a latch shiftably connected with the body and rather closely fitting within the outer barrel, and a part on the latch cooperating with the openings and held therein by the fit of the latch in the outer barrel.

5. In a core drill, an outer barrel, an inner barrel arranged in the outer barrel and having circumferentially spaced openings in its wall, a valve for the upper end of the inner barrel comprising a body arranged in the upper portion of the inner barrel and having sockets communicating with the openings, latches pivoted to the body to depend between the inner barrel and the outer barrel, and parts on the latches cooperating with the openings and sockets and held therein by the cooperation of the latches with the outer barrel.

JOHN H. HOWARD. ALFRED C. CATLAND. 

